Spark-plug.



o one-half FFI@E.

WILLIAM J. LINN, or rIrTsBunGH, PENNSYLVANIA.

SPARK-PLUG.

Specification of Letters Patent.

Patented Nov. 2"?, 191W.

f Application led January 23, 1917. Serial No. 143,928.

5 State of Pennsylvania, have invented certain new and useful Improvements in Spark- Plugs, of which the following is a specilication.

My invention relates to improvements in spark'plugs, and has for its primary object to provide an improved spark plug having perfectly protected firing points which constantly scour themselves clean.

Another object of my invention is to provide a spark plug of the type herein described which is gas-tight, oil proof and clean, thereby eliminating short circuiting.

A still further and important object of the invention is to supply a device of the character set forth, provided with an electrode that will assure an intensified spark.

Still further objects of the invention are to provide a spark plug of the type specified which is simple in its construction and arrangement, strong, durable and highly efflcient in its use, and comparatively inexpensive to manufacture.

To the accomplishment of these and such other objects as may hereinafter appear, the

0 invention consists of the novel construction,

combination and arrangement of parts herein specifically described and illustrated in the accompanying drawing, wherein is shown an embodiment of the invention.

In the drawing, forming a portion of this specification and wherein' like numerals of reference designate corresponding parts throughout the several views:

Figure 1 is a side elevational view, the ortion of which illustrates the outline o a spark plug in accordance with my invention, and the other one-half portion showing a longitudinal cross-section thereof.

Fig. 2 is a perspective view of the center electrode, with the tube containing the mercury partially broken away. y

Fig. 3 is an end view of the bushing.

Fig. 4 is a side elevational View of the bushing, showing a portion thereof in crosssection.

Fig. 5 is an end view of the insulator core or porcelain.

Referring more in detail to the drawing there is shown in Fig. l my improved spark plug comprising the stock or shell 1, the

insulating core or porcelain 2, the center electrode 3, the bushing 4, the terminal or contact nut 5, the asbestos lined gasket 6 and the firing point 7.

The shell 1 is similar to 'those now ordinarily in use and is provided with the usual threaded shank 8. In most of the spark plugs now on the market, the insulating core 2 is positioned `within the shell so that the end of the insulating core, carrying the electrode liring point 9 is nearly flush with or recedes from the open end of the threaded shank 8. In carrying out the principle of my invention, I position the insulating corel 2 within the shell 1 in such a manner that the end l0 thereof will extend decidedly beyond the open end of the threaded' shank 8.

The end 10 of the insulating core 2 is further provided with the annular groove 11 and with the slots 12.

y constructing and positioning the insulating core 2, as heretofore described, I have found by actual tests and experiments that the liability of short circuiting is entirely1 obviated as all accumulations concomitant to its operation are intercepted by the arrangement of the slots 12 and the annular groove 11. Furthermore, the firing point 7 and the electrode liring point 9. will obviously be self-cleaning, owing to the construction of the end 10 of the insulating core 2, which tends to deflect any accumulation that might form thereon.

The center electrode, used in conjunction with my improved spark plug, consists of the metal rods 13a and 13, which are .provided with the threaded ends 14 and 15 respectively, adapted to engage the tapped inner surface 16 of the tube 17. The tube 17 is made from any suitable insulating material, such as fiber, rubber, glass, etc. A small quantity of mercury 18 is imprisoned between the adjacent ends 14 and 15 of the rods 13EL and V13, withinfthe tube 17. Before hermetically sealing the tube 17, the points 14 and 15 are so adjusted to leave the clearance 19 between the mercury 18 and one of the ends 14 or 15, depending on the position of the spark plug.

The mercury 18 is not liable to evaporation as the tube 17, containing the same, is air-tight, and the temperature sufliciently ov for its successful operation and stai ity.

The eciency of the spark plug is greatly lill@ augmented by the of the electrode 3E hereinbeore described, as the mercury 18 carried in the tube 17 will. intensify .the.spahrk.

ing. The electrode 3 is provided with the firing j point 9, which'has a comparatively large .face 20, and when assembled in the insulate.

ing core 2, extends slightly beyond the counterbored opening -21 in the end 10fof'* IloV the insulating core 2, as illustrated in Fig. 1

'of thefdrawingf l I he electrode is rigidly set, by means of the cement 22`and thel compression-nut 23, inthe hole 24 which extendslongitudinally :'16 through vtheinsl'ilating core 2.-

The insulating core 2 is cushioned .againsttheforce ofthe explosions and is made gastightiby the lined gasket 6 against one side [of the shoulder 25 on" the'insulating core 2, 20,and bythe specially designed bushing y4 against the opposite thereof.

-. `The bushing' il dilfers'inaterially from any bushingnow in use in' thatit'is constructed witha groove 26, forming the inner wall 27 and .the .outer wall 28. Thel inner wall 27 is slightly shorter than the outer wall 28 and ijs provided with the 'bevel 29. WhenV assembling my improved vspark ping the bushing i is Screwed into the shell 'Mg -1,.and owingto the groove 26 and the bev- 'ffeled inner wallf 27gof`thebushing 4, the inner wall 27 willreadily conform itself to the contourfof theshoulder 25 against which it isforced. The,constrl'ictionof my improved 3o bushing l obviates the necessity of employ- 2Q'o the'elect'r'ode Iiring point 9. The firing point ,9 maybe ymade detachable fromthe require it.

l The usual'threadedend 30, on the elec`A trode 3 y is'pjovidelV for thelengagement of-` the compression' nut 23' and the terminal or,

y :contact nut.

L p Eronitheiforegoing descript1on,*taken in connection with the accompanying' drawing,

the advantages lofthe 'construction and of the method of operation will be readily apthe invention appertains, and while'I have described the principle of operation of the invention, together with the device which I 'Gli now `consider to be the best embodiment' and passing over -the groove.

shownI inFig. 1 of the drawing, 'thefiring point"7,"'a1ttached to the threaded`- slijank', extends entirely across the surface "'parent to ythoseskilled in the art to which thereof, Idesirento havegit 'understood that the device shown is merely illustrative and thatA suchk changes may be resorted to when desired las are within "the scope of the claims appended hereto.

What I claim is 1 A spark plug comprising a shell, a core supported by the shell having a Aflared extremity, an kelectrode connected i to the shell and passing over the flared extremity, a second electrode supported bythe core composed of two members adjustably connected and one of which; having, a ilared extremity opposite VSaid' iirst, electrode the flared-end of said corevbeing. provided with,

intersecting passages. s

H 2. ,A spark plug comprising. ashell, a core supported by the shell having'a flared. extremity, an electrode connected tothe shell the flared extremity, a sec- .1

ond electrode supported by l,theore composed of tw-o members adjustably `connected and one of which having aflaredextremity opposite said irst electrode, said flared end ofthe core being providedwith a circumferential groove land. slots intersecting 3. A spark plug comprisinglfashell, a. core having a flange ysupported by the shell, a

bushing adjustably mounted in the shell and having a -groovedxilange yieldablywem gaging. said iirsujiange,` an electrode connected to the gshell, a .second electrode supported bythev core` and composed of'QlVO members and a tube suppertingthe"rhein- ,V bers for 'adj ustment towardmand away from" each other and a quantityl of conducting fluid supported bythe tubeV between the opposing endsof said member.

4'.. A spark plug comprising 'a shell,l havingV a flange supportedvby Y the shell, av bushing adjustablymountedfin the'shell and having. a grooved ilange yieldably engaging said' first flange,- an .electrode [connected: to the shell, a second .electrode supported by the core and composed oftwomembers and a tube supporting the .'membersy for', adjustment toward and,` away. fronr each'otlier and a quantity of mercury supportedby the' tube electrode 3; whifclfwould allow' the said iringxpoints to' be'replaced shouldA occasion.

`between the opposing x enfdsoj4 ,saidjfiiiember l and a lcementitious; materifa`l l arranged l be? ftweenthe members andtliecorelqfj;

- 5.\In a spark lug,.an electrodoolsisting vvof two members andmeansffojr `ad justably connecting the members .to ether y for yaryf ing the distance.therebetween, ]r I 6.' In a sparkplug, anleletr de consisting of two members and line/1111s onadjustably 8. in a spark ping, e core forming e cenemi fuere, en eleorode arranged in the bore consisting of :two members edjusteoly connected and a Eller between the electrode and the mii of seid bore.

9.. En a spark plug, a core forming e eem irai bore, an dect-rode airenged in the boie consisting ef two membezs adjusmbiy mib nested and e eemeniious meterie for eceomplishing a rigid eomiectien between the members anni WeB of the bere.

@ogpe ei gemene may be elimine@ foe me @ems each,

l0. in e speel; plug, e core forming e een im! bore, an eeetyode zii-ranged in lie heie consisting of two members, a, tube of iiisulating material having screw threaded e11- gagement Wiih the .member end e sementitous mateiiel for aeeomplishing e, rigid eenneotion between. the members and Weil of the bore.

In testimony whereof my signature the presence of two Witiiesses.

VULLIAJV Lifiil Wienesses:

JENNUS JONES,

R. CLEMENT Weemmmsem, E. Q5. 

